[gnome-games] ui: Add GameThumbnail.invalidate_cover()

[Adrien Plazas <aplazas src gnome org>]

commit 72c88f322ccd9364d3545933ffc428d87faa960e
Author: Adrien Plazas <kekun plazas laposte net>
Date:   Wed Jul 13 08:52:51 2016 +0200

    ui: Add GameThumbnail.invalidate_cover()
    
    This will be used in the next commit to invalidate the cover cache.

 src/ui/game-thumbnail.vala |    8 ++++++--
 1 files changed, 6 insertions(+), 2 deletions(-)
---
diff --git a/src/ui/game-thumbnail.vala b/src/ui/game-thumbnail.vala
index 64aacf7..b40a79f 100644
--- a/src/ui/game-thumbnail.vala
+++ b/src/ui/game-thumbnail.vala
@@ -41,9 +41,9 @@ private class Games.GameThumbnail: Gtk.DrawingArea {
                        _cover = value;
 
                        if (_cover != null)
-                               _cover.changed.connect (queue_draw);
+                               _cover.changed.connect (invalidate_cover);
 
-                       queue_draw ();
+                       invalidate_cover ();
                }
                default = null;
        }
@@ -198,6 +198,10 @@ private class Games.GameThumbnail: Gtk.DrawingArea {
                }
        }
 
+       private void invalidate_cover () {
+               queue_draw ();
+       }
+
        private void draw_pixbuf (DrawingContext context, Gdk.Pixbuf pixbuf) {
                var surface = Gdk.cairo_surface_create_from_pixbuf (pixbuf, 1, context.window);